There are many factors that contribute to the proper application of the heating, ventilation, and air conditioning (HVAC) systems in houses. Selecting the most efficient type, size, and placement of the system takes careful planning and study by qualified HVAC contractors and is dependent on the heat load demand, location, and orientation of your house – to mention some considerations. Different regions of the country have varying heat load demands so differing systems selection and installation should be expected. This discussion does not intend to cover all aspects of the systems but rather provide general information on the common systems in houses.
Central Heating and Air Conditioning Systems
These systems are characterized as a split system (meaning the condensing unit is located outside with the heating unit and evaporator coils located in the house), forced air (blower/fan unit), ducted system. The condensing unit is the mechanical unit seen in the exterior lawn. The evaporator coil of the air conditioning unit along with the heating unit and the blower/fan unit are in the house – usually a basement, attic, or interior closet. A duct system distributes the treated air throughout the house.
Package unit systems are like central heating and air condition systems in the use of a duct system to distribute treated air. However, the heating and air conditioning components are in one cabinet, typically located in the lawn or on a roof platform.
Portable Wall Mount Units
These individual units are often installed in windows or openings in walls. They are small and portable for easy transfer from one room to the next or one building to the next. Portable units will generally serve one room, so multiple units are needed to heat or cool large areas. Portable wall mount units may provide air conditioning, only, or may provide heating by the heat pump feature of the unit.
Mini-split systems provide heating and air conditioning comfort to very localized regions of a house, often only one or two rooms. The split system is like the central heating and air conditioning system in concept except there is no blower/fan or duct system to distribute conditioned air throughout the house. Typically, a small condenser is placed in the adjacent lawn and a wall-mounted, evaporator coil is in the room to be conditioned. Heating is provided by the heat pump feature of the unit.